Introduction

4

Freescale

Sensor Fusion Library for Kinetis MCUs, Rev. 0.7, 9/2015

Freescale Semiconductor, Inc.

Table 1. Feature Comparison of the Freescale Sensor Fusion Algorithm Options

Feature

Accel only

Mag only

Gyro Only

Accel + gyro

Accel + mag

Accel + mag + gyro

Filter type

Low pass

Low pass

N/A

Indirect Kalman

Low pass

1

Indirect Kalman

Roll / Pitch / Tilt in degrees

Yes

No

Yes

Yes

Yes

Yes

Yaw in degrees

No

Yes

Yes

No

Yes

Yes

Angular rate

2 in degrees/second

virtual 2 axis

3

Yaw only

Yes

Yes

virtual 3 axis

Yes

Compass heading (magnetic north) in

degrees

No

Yes

No

No

Yes

Yes

Quarternion and rotation vector

Yes

Yaw only

Yes

5

Yes

Yes

Yes

Rotation matrix

Yes

Yaw only

Yes

5

Yes

Yes

Yes

Linear acceleration separate from gravity

No

No

No

Yes

No

Yes

NED (North-East-Down) frame of reference

Yes

4

Yes

Yes

4

Yes

4

Yes

Yes

ENU (Windows 8 variant) frame of reference

Yes

4

Yes

Yes

4

Yes

4

Yes

Yes

ENU (Android variant) frame of reference

Yes

4

Yes

Yes

4

Yes

4

Yes

Yes

Magnetic calibration included

N/A

Yes

N/A

N/A

Yes

Yes

Gyro offset calibration included

N/A

N/A

No

Yes

N/A

Yes

FRDM-KL25Z board support

Yes

Yes

Yes

Yes

Yes

Yes

FRDM-KL46Z board support

Yes

Yes

Yes

Yes

Yes

Yes

FRDM-K20D50M board support

Yes

Yes

Yes

Yes

Yes

Yes

FRDM-KL26Z board support

Yes

Yes

Yes

Yes

Yes

Yes

FRDM-K64F board support

Yes

Yes

Yes

Yes

Yes

Yes

FRDM-K22F board support

KDS only

1.

More precisely: a non-linear modified exponential low pass quaternion SLERP filter.

2.

Angular rate for 6 and 9-axis configurations with a gyro include corrections for gyro offset.

3.

Subject to well-known limitation of being blind to rotation about axes aligned with gravity.

4.

These solutions do not include a magnetometer, therefore there is no sense of compass heading.

5.

Rotations for gyro-only solution are relative to sensor position (there is no global frame).